The present disclosure generally relates to fabrication of three-dimensional objects, and more specifically, to selective inhibition of bonding for layered fabrication of such objects.
Three-dimensional (3-D) objects, such as prototype parts, may be produced directly from computer-aided design databases. Various technologies are known to produce such objects, particularly through the use of layered additive processes. One of these processes (SLS) works by depositing and heating powder material at selected locations, to bond the material to the layer below. Commercially adapted methods of layered manufacturing use various forms of materials. For example, stereolithography (STL) uses a resin called photopolymer that is selectively hardened by a laser beam delivering UV light at desirable spots on each thin resin layer. Fused Deposition Method (FDM) uses a plastic filament that is forced through a hot nozzle that deposits the material to form each layer. Laminated Object Manufacturing (LOM) laminates cut sheets of a special paper to create 3D parts. Selective Laser Sintering (SLS) selectively bonds powdered material using laser. The powder material may include polymer, ceramic, or metal. Another method referred to as Three-Dimensional Printing uses adhesive droplets deposited on each thin powder layer to create bonding of powder particles in selected spots of each layer.
However, the above-described methods for layered manufacturing present difficulties with respect to time, cost, and quality of the produced 3-D objects. For example, those methods that use a laser incur the high cost:of the laser and the low scanning speed due to relatively wide cross-section area per layer for sintering compared to the beam size. For other methods, difficulties lie in tediously slow process of scanning the entire volume of the object, layer by layer, by sintering or other fusion process. Furthermore, when sintering or heating a selected area, a relatively uniform temperature needs to be maintained on the powder surface in order to prevent deformations.
In recognition of the above-described difficulties, the inventor recognized the need for a 3-D fabrication of objects that provide faster and cheaper method and system than the conventional method.
In one aspect, the present disclosure describes a method for fabricating a three-dimensional (3-D) object. The method includes providing a layer of powder material, and selectively depositing bonding inhibitor on selected areas of the layer of powder material. The areas to be deposited with the bonding inhibitor are selected according to a cross-section design of the 3-D object. The method also includes a step of promoting bonding of uninhibited areas of the entire layer of powder material. The method further includes repeating the steps of providing a layer of powder material, selectively depositing bonding inhibitor, and promoting bonding of uninhibited areas until the 3-D object is formed.
In another aspect, the method includes a step of providing a layer of powder material, and selectively depositing bonding inhibitor on selected areas of the layer of powder material. The areas to be deposited with the bonding inhibitor are selected according to a cross-section design of the 3-D object. The method also includes repeating the steps of providing a layer of powder material and selectively depositing bond inhibitor, until entire programmed layers of the 3-D object has been deposited. The entire programmed layers of the 3-D object may then be sintered in a sintering oven.
In further aspects, the present disclosure describes apparatuses configured to perform the above-described methods.